E3 ubiquitin-protein ligase RNF144B; IBR domain-containing protein 2; RING finger protein 144B; p53-inducible RING finger protein (RNF144B, IBRDC2, P53RFP)

Function

• E3 ubiquitin-protein ligase
• induces apoptosis via a TP53/p53-dependent but caspase-independent mechanism
• overexpression produces a decrease of ubiquitin-dependent stability of BAX, a pro-apoptotic protein, ultimately leading to protection of cell death
• protein modification; protein ubiquitination
• auto-ubiquitinated
• interacts with UBE2L3, UBE2L6 & LCMT2, as well as with BAX

Structure

• the RING-type Zn+2 finger domain mediates binding to an E2 ubiquitin-conjugating enzyme (putative)
• the transmembrane domain is essential for translocation to the mitochondria upon induction of apoptosis
• belongs to the RBR family, RNF144 subfamily
• contains 1 IBR-type Zn+2 finger
• contains 2 RING-type Zn+2 fingers

Compartment

• mitochondrial membrane
• cytoplasm
• mostly cytosololic
• accumulates in submitochondrial domains specifically upon apoptosis induction, in synchrony with BAX activation

Expression

• broadly expressed
• highest expression in heart, ovary & testis
• lowest expression in brain & thymus

Notes

• lacks the His in the RING-type domain 2 that is one of the conserved features of the family

More general terms

• E3 ubiquitin ligase
• mitochondrial protein
• ring finger protein
• membrane protein

Additional terms

• IBR domain-containing protein (IBRDC)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=255488
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:255488
• UniProt: http://www.uniprot.org/uniprot/Q7Z419.html